CAD of schematics and PCBs

Computers have evolved rapidly over the past few years, and are now used for
design work that was long thought to be possible by hand only. In modern CAD
systems, for instance, computers have taken over from the traditional pen, paper
and ruler. These tools are now completely replaced by advanced screen
operations. In the field of electronics, too, many aspects of design have been
taken over by the computer. The aim of this article is to show how an electronic
circuit plus associated printed circuit board can be designed rapidly and
efficiently with the aid of a computer.